An 18-year-old man is evaluated due to worsening headaches. For the last several months, the patient has had intermittent, dull, occipital headaches, which are often brought on by physical activity, cough, or straining. The pain is usually accompanied by nausea and dizziness, and the symptoms spontaneously resolve after several minutes. There is no history of fever, chills, photophobia, vision disturbances, or focal weakness or numbness. He has no prior medical conditions and takes no medications. Vital signs are normal. Physical examination, including neurologic examination, shows no abnormalities. MRI of the head is shown in the image below: This patient is at greatest risk for which of the following in association with his current condition?

Question

An 18-year-old man is evaluated due to worsening headaches.  For the last several months, the patient has had intermittent, dull, occipital headaches, which are often brought on by physical activity, cough, or straining.  The pain is usually accompanied by nausea and dizziness, and the symptoms spontaneously resolve after several minutes.  There is no history of fever, chills, photophobia, vision disturbances, or focal weakness or numbness.  He has no prior medical conditions and takes no medications.  Vital signs are normal.  Physical examination, including neurologic examination, shows no abnormalities.  MRI of the head is shown in the image below:  This patient is at greatest risk for which of the following in association with his current condition?

Quizplus · Accepted Answer

11ec25c8_d577_fcc7_bc81_77106aa3b67d_MD0003_00 This patient's MRI reveals a Chiari malformation, an anatomic abnormality characterized by inferior displacement of the cerebellum through the foramen magnum. In general, the cerebellum sits within the posterior cranial fossa and above the foramen magnum, which contains the medulla, nerves, and vasculature. When only the cerebellar tonsils are displaced, as seen here, the defect is referred to as a Chiari I malformation (CM-I). A Chiari II malformation, which is associated with myelomeningocele, includes herniation of the cerebellar tonsils and vermis as well as inferior displacement of medulla. Chiari III malformations are severe and involve herniation into an encephalocele. cerebellum Chiari II malformation CM-I is the most common and mildest subtype and is frequently asymptomatic throughout childhood. Patients may be diagnosed incidentally on imaging or present in adolescence or early adulthood with occipital headache and/or neck pain. Dizziness and worsening pain classically occur with physical activity or Valsalva maneuvers (eg, cough, straining) due to pressure of the cerebellar tonsils on the foramen magnum. Other findings of CM-I can include increased intracranial pressure, cranial neuropathies from brainstem compression (eg, dysarthria), and cerebellar dysfunction (eg, ataxia). Syringomyelia, a disorder in which a cyst (syrinx) forms in the spinal cord, occurs in about 30% of CM-I. The syrinx is most commonly located in the cervical region, and progressive neurologic dysfunction (eg, paresthesia, weakness) can occur with syrinx expansion. Scoliosis may be the only sign of syringomyelia in children and may prompt an early diagnosis of CM-I. (Choice A) Cardiac rhabdomyoma is associated with tuberous sclerosis complex, a neurocutaneous disorder in which subependymal nodules and cortical glioneural hamartomas are typically present on brain MRI. tuberous sclerosis complex (Choice B) Optic neuritis is commonly associated with multiple sclerosis, a demyelinating disorder of the CNS. MRI would reveal demyelinated plaques in the brain and/or spinal cord. demyelinated plaques (Choice C) Parathyroid adenomas, as well as pituitary and pancreatic tumors, are associated with multiple endocrine neoplasia type 1. A pituitary mass may be present on brain MRI. pituitary mass (Choice E) Vestibular schwannomas (acoustic neuromas) occur in most patients with neurofibromatosis type 2 and, in addition to meningiomas and ependymomas, may be seen on brain MRI. Vestibular schwannomas Educational objective: Chiari I malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, and syringomyelia is a commonly associated condition. Although frequently asymptomatic, presentation may occur in adolescence/adulthood with occipital headache exacerbated by activity and Valsalva maneuvers. References: Chiari malformation and syringomyelia. (http://www.ncbi.nlm.nih.gov/pubmed/31675698) Prevalence of Chiari I malformation and syringomyelia. (http://www.ncbi.nlm.nih.gov/pubmed/26408058)

An 18-Year-Old Man Is Evaluated Due to Worsening Headaches